(±)5-HETE, a monohydroxy fatty acid, emerges from the non-enzymatic oxidation of arachidonic acid and is one of six such derivatives. Its methyl ester variant exhibits no unique biological activity and serves as a provided standard. This methyl ester can also be present in oxidatively degraded polyunsaturated fatty acid (PUFA) methyl esters.
"(±)11-HEDE, a racemic mixture comprising the monohydroxy fatty acids 11(S)-HEDE and 11(R)-HEDE, is synthesized from eicosadienoic acid via cyclooxygenase (COX) activity and within macrophages."
5(6)-DiHET is a racemic compound synthesized through the action of epoxide hydrolases on 5(6)-EET, encompassing both enantiomeric forms. It serves as a quantitative marker for 5(6)-EET, facilitating its measurement by utilizing the compound's conversion to 5(6)-δ-lactone in solution. Additionally, 5(6)-DiHET activates large-conductance calcium-activated potassium (KCa1.1/BK) channels in rat small coronary artery smooth muscle cells, supporting its biological significance in vascular regulation. It also acts as a substrate for sheep seminal vesicle COX, leading to the in vitro production of 5,6-dihydroxy prostaglandin E1 and F1α metabolites. Notably, its levels diminish in the plasma of rats subjected to a high-fat diet, indicating a potential role in the pathophysiology of hyperlipidemia.